That would be cloud-based life science software provider Veeva Systems of Pleasanton, which hit a $4.4 billion market cap when it went public last fall after raising just $4 million in funding. That was an 1,100-fold return on investment for sole venture backer Emergence Capital Partners of San Mateo, which owned 30 percent of the company led by founder and CEO Peter Gassner.

Of course, Veeva's value has since dropped to about $2.5 billion amid this spring's big drop in cloud-based software company stocks.

But the CB Insights ranking is based on "capital efficiency," or bang for the buck, on the date a company was bought or went public. It also only worked with exits that topped $100 million, in order to discount outliers at the lower end of the scale.

It's an impressive list.

WhatsApp, founded by former Yahoos Jan Koums and Brian Acton, paid about 317 times investment. It likely brought in billions more to Sequoia Capital, which had invested $60 million in the Santa Clara-based company, than what Emergence is getting. But that is another small bone to pick when talking these types of returns, isn't it?

Connecticut-based job search company Indeed is No. 3. The company, which has since moved its headquarters to Austin, Texas, was acquired for more than $1 billion by Japan's Recruit Co. in September 2012. It had raised just $5 million from investors — which included the New York Times, Allen & Co. and Union Square Ventures. That works out to a 280-fold return.

Seattle-based Tableau Software is the only other exit on the list that topped 100-fold in its payoff to investors. The Big Data company raised just $15 million from New Enterprise Associates and Meritech Capital Partners before going public a year ago with a market cap of about $2.9 billion.

Silicon Valley is home to 14 of the top 25 exits on the CB Insights tally. In all, these top U.S.-based tech companies exited with an aggregate valuation of about $158 billion after raising just $3.35 billion.

Here is the ranking of the best returns compiled by CB Insights. Bay Area companies have an asterisk: